The impact of increased national wealth, as measured by Gross Domestic Product (GDP), on public health is widely understood, however an equally important but less well-acclaimed relationship exists between improvements in health and the growth of an economy. Communicable diseases such as HIV, TB, Malaria and the Neglected Tropical Diseases (NTDs) are impacting many of the world’s poorest and most vulnerable populations, and depressing economic development. Sickness and disease has decreased the size and capabilities of the workforce through impeding access to education and suppressing foreign direct investment (FDI). There is clear evidence that by investing in health improvements a significant increase in GDP per capita can be attained in four ways: Firstly, healthier populations are more economically productive; secondly, proactive healthcare leads to decrease in many of the additive healthcare costs associated with lack of care (treating opportunistic infections in the case of HIV for example); thirdly, improved health represents a real economic and developmental outcome in-and-of itself and finally, healthcare spending capitalises on the Keynesian ‘economic multiplier’ effect. Continued under-investment in health and health systems represent an important threat to our future global prosperity. This editorial calls for a recognition of health as a major engine of economic growth and for commensurate investment in public health, particularly in poor countries.